Shimer and Blodgett — Mt. Taylor Region, New Mexico. 57 



he cites Stantonoceras stantoni as from strata of Cretaceous 

 age. The fauna is thus of undoubted Colorado age, though the 

 presence of the Placenticeras f rolundatum would indicate 

 that it was not of the lowest Fort Benton. 



The slight northerly dip of these beds causes the septaria zone 

 with its capping of sandstone, seen immediately south of Salazar 

 at about the level of the town, to disappear a short distance 

 north of the town beneath the flood plain of the Rio Puerco. 

 The succeeding strata thus brought into view consist of an alter- 

 nation of dark shales and brownish yellow shaly sandstones. 

 This alternation continues practically to the divide southwest 

 of Cabezon peak with a much greater predominance of sandstone 

 in the upper beds entered to the north. Thus as the river flows 

 south it enters lower and lower beds. 



Neck 3. — At the eastern side of this neck some fossils were 

 collected from the strata on the western side of the road at 

 distances varying from 30 to 100 feet from the base of the neck. 

 These fossiliferous beds are yellowish shaly sandstones. The 

 following fossils were found here : 



Trigonarca depressa White 



Lucina cf. subundata H. and M. 



jPteria linguiformis (E. and S.) 



Solemya f obscura Stanton 



Pinna sp. 



Actceon propinquits Stanton 



Plant remains in extremely minute fragments are very abun- 

 dant in many strata. 



Actceon propinquus and Solemya f obscura were found by 

 Stanton in the Pugnellus sandstone (upper Fort Benton) of 

 Colorado, and thus are there characteristic of the Fort Benton. 

 Pteria linguiformis is of Montana age and the type of Lucina 

 subundata of Fort Pierre, though this latter is found at Upper 

 Kanab, associated also with a Colorado fauna. Trigonarca' 

 depressa has apparently not been found outside the valley of 

 the Rio Puerco; the type was found in lower strata six miles 

 south of Salazar on the east side of the river. While thus two 

 species are characteristic of the upper Fort Benton and one of 

 the Montana, with one occurring in both, an uppermost Fort 

 Benton age for the fauna would appear to be indicated, unless 

 we suppose that the apparent absence of clear water here dur- 

 ing Niobrara time w T oulcl cause the absence of the typical Nio- 

 brara fauna and a persistence of the Fort Benton fauna to 

 Montana times. These strata under such a supposition might 

 represent the Niobrara time without the typical Niobrara fauna. 



Fossiliferous stations southeast of Cabezon peak. — A little 

 northeast of Prieta mesa, as the road enters the Jemez sheet, 

 and thence to Sierrita mesa, the strata have a slight westerly 



